Dsi Homebrew load bmp from sdcard

Question

So i'm trying to display an bmp image stored in the sdcard of the dsi I have found this code:

consoleInit ( 0, 1, BgType_Text4bpp, BgSize_T_256x256, 0, 6, false, true); //für das untere Bildschirm

    FILE *pFile=fopen ("TTMenu/Starter/Down.bmp","rb");

    if (pFile!=NULL)   {
      //file size
      fseek (pFile, 0 , SEEK_END);
      long lSize = ftell (pFile);
      u8 *buffer= (u8*) malloc (sizeof(u8)*lSize);
      rewind (pFile);

      if (fread (buffer,1,lSize,pFile) != lSize)
         printf("\n Datei kann nicht gelesen werden\n"); //File could not be read

      //copy from buffer
        //dmaCopy(buffer, BG_GFX_SUB, lSize);
        decompress(buffer, BG_GFX_SUB, LZ77Vram);

      //close file and clean buffer
      fclose (pFile);
      free (buffer);
    }
    else printf("\n Datei wurde nicht gefunden!\n"); //File not found

and after trying it the file is read because << Datei wurde nicht gefunden >> DOESN'T apear on the screen I'm a beginer in c++ (not a big one but still) and I'm searching on how to display this image. The question is how to display the image form the sdcard